Method and apparatus for injecting fluids into earth formations



May 9, 1967 H. BRANDT 3,318,381

METHOD AND APPARATUS FOR INJECTING FLUIDS INTO EARTH FORMATIONS Filed Sept. 30, 1964 3 SheetsShee1-, 1

ClRCUIT FOR ACETONE 25\ DIESEL SOLENOID VALVES SHAPED CHARGES 26 27 AND DOWN HOLE METERS RESIN ACTIVATOR 17 /a 6 INVENTOR HARRV BRANDT A May 9, 1967 H. BRANDT &

METHOD AND APPARATUS FOR INJECTING FLUIDS INTO EARTH FORMATIONS Filed Sept. 30, 1964 s Sheets-Sheet p,

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W ll/I INVENTOR HARRY BRANDT United States Patent Ofiice 3,318,381 Patented May 9, 1967 3,318,381 METHGD AND APPARATUS FOR INJECTING FLUIDS INTQ EARTH FORMATIONS Harry Brandt, Davis, Califi, assignor to @hevron Research Company, a corporation of Delaware Filed Sept. 30, 1964, Ser. No. 480,444 Claims. (Cl. 16635) In oil recovery operations and particularly in oil well completion and recompletion work, it is often necessary to practice sand control, i.e., to prevent or greatly reduce flow of sand into a well. Sand control has heretofore been accomplished by a number of methods. For example, gravel or sand packing of the space between the perforated well casing and the formation has been done to deter sand flow. Prepacked sand control liners formed about perforated tubing have also been inserted into Wells and positioned adjacent producing formations to help prevent sand flow up the production tubing. More recently, methods have been devised to consolidate the formation sand in place behind perforated well casing by injecting a binding material into the formation to contact the loose sand and to consolidate the sand when the binding material sets up.

When the last-mentioned sand consolidation process is used in actual practice it is necessary that the sand consolidation liquids be injected uniformly over the formation interval which is to be consolidated. The producing formation where consolidation by this method is desired may be a thick section having greately dilferent permeabilities over the interval to be consolidated. The consolidation liquids, of which usually there are at least two, typically have different viscosities. Thus, when it is desired to consolidate a permeable interval of a formation, it becomes diflicult to ensure that the consolidation liquids are evenly distributed over the entire interval.

As is known in the petroleum producing art, a perforated casing is used to line a producing interval. Spaced over the length of the casing are perforations through which oil can flow into the well. Usually the distance between perforations is a foot or less. Since the formation behind the perforations may not have uniform permeability the sand consolidation fluids that are injected into the formation will not be distributed uniformly around the Well bore. It is, therebore, a difficult problem to obtain even distribution of the injected liquids over the selected interval to be consolidated.

In a broad aspect, the present invention provides methods and apparatus for use in consolidating incompetent underground formations penetrated by a well. The apparatus of the present invention is useful to provide uniform or nearly uniform injection of the consolidation fluids throughout the vertical interval of the formation to be consolidated. The consolidation apparatus comprises a main body member insertable into a well and having a central opening. The body member is connect able to a supply tubing to establish a flow path from the earths surface to the central opening of the main body member. Movable packing means are provided on the main body member and are extendible from the body member to a position against the casing or wall of the well to form liquid-tight zones thereabout. Casing penetrating means for penetrating the well casing may be provided to act in cooperation with the packing means to perforate the casing within the liquid-tight zones if necessary. Flow path means are provided in the main body member and communicate with the central opening of the main body member to provide a flow path through the main body member to each of the perforations in the casing packed off by the packing means for the injection of liquid into the formation. Metering means and valve means are positioned in each of the flow path means to meter and control the amount of fluid entering each perforation.

It is a particular object of the present invention to provide methods and apparatus for injecting predetermined amounts of consolidation liquids through at least two perforations of a cased well in a manner to ensure that each perforation receives substantially equal amounts of said consolidation liquids.

Further objects and advantages of the present invention will become apparent from the following detailed description of the invention read in light of the accom panying drawings which are made a part of this specification and in which:

FIGURE 1 is a diagrammatic view of a portion of an earth formation penetrated by a well and is an illustration on enlarged scale of apparatus assembled in the Well in accordance with the present invention;

FIGURE 2A is a sectional view illustrating the upper portion of a preferred embodiment of apparatus assembled in accordance with the present invention;

FIGURE 2B is a sectional view illustrating the middle portion of a preferred embodiment of apparatus assembled in accordance with the present invention;

FIGURE 20 is a sectional view illustrating the lower portion of a preferred embodiment of apparatus assembled in accordance with the present invention;

FIGURE 3 is a sectional view taken at line 33 of FIGURE 2B;

FIGURE 4 is an elevation of a portion of the preferred embodiment of apparatus;

FIGURE 5 is a longitudinal section taken at line 5-5 of FIGURE 4;

FIGURE 6 is a sectional view taken at line 6-6 of FIGURE 5;

FIGURE 7 is a sectional view taken at line 7-7 of FIGURE 5.

Referring now to the drawings and to FIGURE 1 in particular, a general arrangement of apparatus assembled in accordance with the present invention is diagrammatically shown. In that illustration, the formation that is to be consolidated, for example, an oil producing formation, is represented by the numeral 20. A well 19 extends from the surface and penetrates formation 20. The Well 19 has been cased as is usually the practice in the art with a suitable string of casing 21. Cement 22 or other suitable grouting material has been forced between the casing 21 and formation 20 to seal the annular space therebetween.

A tubing string 23 extends from the surface to at least a location substantially adjacent to the producing formation 29. The tubing 23 provides a flow path from the surface to a position adjacent the producing formation 2!).

Suitable sources of sand consolidation liquids, for example, acetone 24, diesel 25, resin 26, and activator 27 are connected by suitable tubing 29 and valves 10, 11, 12, and 13 through a pump 28 to tubing string 23. Suitable compositions and methods for consolidating an incompetent earth formation are described and claimed in US. application Ser. No. 218,537, now US. Patent No. 3,250,764 of which I am coinventor.

In accordance with the invention, means such as donutshaped packing rings 30 and 31, are provided to pack off portions of the casing 21 at a position adjacent to the producing formation 20. The packing rings 30 and 31 are extendible against the casing and form liquid-tight seals inside the hole portion of the donut-shaped rings to pack off .a zone of the casing. Suitable hydraulic means are provided to extend the packing ring assembly from the tool and against the casing thereby causing the packing rings 30 and 31 to seal. For example, the packing rings may be carried on a movable frame 16 which can be extended against the casing by piston means When fluid under pressure is forced into tube 5. Resilient means 8 and 9 act to normally retain the frame 16 retracted against the tool body.

As illustrated in FIGURE 1 the present description deals with a. completion in which it is necessary or desirable to form new perforations in the casing. As described later it is also possible to use the present apparatus to inject fluids into wells where the casing is already perforated. However, in completions where it is necessary to form the perforation, shaped charge perforating means 32 and 33 are positioned in a manner so as to perforate the casing inside the zone packed off by the respective packing rings 30 and 31. The shaped charges 32 and 33 are fired electrically from the surface by means of suitable electrical conductors such as wire 18 and the tubing string. After the shaped charges have been fired and the casing perforated, a flow path from the surface to the perforations is provided by means of tubing 23 and the small passageways 34 and 36 leading off the main tubing to chamber 35 and chamber 37 formed inside packing rings 30 and 31, respectively.

After the flow paths to the producing formation have been provided as described above, the first of the liquid consolidation agents is injected through tubing 23 by means of pump 28 and through both flow lines 34 and 36 into the producing formation 20. Flow meters 39 and 40 determine the amount of fluid flowing through each of the flow lines 34 and 36, respectively. As described above it is necessary to get the same amount of the liquid through each perforation if the consolidation job is to be successful and economical. The amount of fluid flowing through each of the meters is transmitted by suitable electrical means 17 to the surface. After the predeterminable amount of liquid flows through each of the flow lines, solenoid valves 41 and 42 are closed by suitable means such as cables 6 and 7. Thus, if the portion of the formation adjacent to chamber 35 is more permeable than the portion of the formation adjacent chamber 37 and, therefore, takes liquid faster, solenoid valve 41 is closed after the predeterminable amount of fluid has passed through meter 39. The remaining liquid in tubing 23 is then directed through passageway 36 and chamber 37 and then into the formation.

In FIGURES 2A, 2B and 2C, the preferred embodiment of apparatus assembled in accordance with the present invention is shown. A main body member is generally identified by the numeral 50. The main body member may, for example, be made up of sections 51, 52 and 53. A tubing string 54 is connected to the main body member 50 by suitable means such as threads 55. The tubing string 54 provides a flow path from the surface to the interior of the main body member 50. The main body member is provided with a central flow opening 60 communicating the tubing string 54 and extending through at least a portion of the interior of the member 50. A series of smaller passageways extend down the main member 50 and open into the central flow opening 60. One of these passageways 56 leads to chambers 57 and 157. Pistons 58 and 158 are located in chambers 57 and 157 respectively and urged into the chambers by means of springs 59, 61, 159 and 161. Donut-shaped packing rings 62, 63, 162 and 163 are mounted on the frames 14 and 114 respectively which are movable by means of the pistons 58 and 158. Thus the packing rings 62 and 63 can be extended by means of fluid pressure in chamber 57 exerted on piston 58. Packing rings 162 and 4 163 are also extended simultaneously by means of pistons 158 and frame 114.

Thus in operation the apparatus is run into the well by means of the tubing string 54 to a desired location adjacent to a producing formation. As indicated above the well casing may have existing perforations or it may be necessary or desirable to form new perforations. In either event the packing rings or other suitable packing means are extended against the casing to form fluid-tight zones about each perforation. The packing rings are extended in the preferred embodiment of apparatus by means of exerting pressure on liquid in the tubing and in the main body member.

The central flow opening 60 of body member 50 is closed by spring-loaded valve means 90. The springloaded valve means acts to prevent flow through passageway means 64 until a predeterminable pressure is applied on the liquid in the central flow opening 60 of the main body member 50. The strength of the spring in the valve means is determined by the minimum pressure that it is desired to have the sealing rings 61, 62, 161 and 162 exert on the casing. This pressure is easily determined by one skilled in the art and depends on such factors as formation depth, injection pressure and the like.

When the pressure on the liquid in the central flow opening 60 is increased to a pressure above this minimum the spring-loaded valve means 90 opens to allow flow in passageway means 64. Passageway divides into a plurality of passageways which lead to the chambers inside the packing rings. For the purposes of this description there are shown four passageways 65, 66, 165 and 166 which lead to four chambers and associated packing rings. Thus the apparatus as illustrated can perforate and inject fluid into four locations in the casing. It is understood that the invention is not to be limited to any specific number of units.

Passageway 65 leads to chamber 68 and passageway means 66 leads to chamber 69. The lower chambers 168 and 169 are connected to the central opening 60 by passageways i165 and 166. Initially, the chambers 68, 69, 168 and 169 are closed by face plates 70, 71, 170 and 171, however, when shaped charge means 72, 73, I172 and 173 are fired, the face plates are perforated and chambers 68, 69, 168 and 169 are opened. After the packing rings 62, 63, 162 and 163 have been extended in position against the casing and the shaped charges fired, the consolidating liquid is pumped into the main body member under suflicient pressure to open spring-loaded valve 90 and to be forced through the passageways and out through the perforated casing into the formation.

The amount of flow through each of the passageways 65, 66, 165 and 166 is measured by flow meters 74, 75, 174 and 175, respectively. The flow meters are schematically illustrated and each flow meter includes a means for producing a magnetic field such as magnet 201 mounted by a suitable mount 202. A pivotally mounted vane 203 is placed in each of the passageways and turns in response a fluid flow therethrough. The turning vane changes the magnetic field which in turn produces electrical signals that are sent to the surface by means of suitable electrical conduits 204 and 81. After a predeterminable amount of liquid has passed through each of the various passageways each passageway can be closed by means of a suitable valve, such as a solenoid valve '78. The solenoid valves 78 and 79 are schematically illustrated and each valve includes a valve stem 210 for closing the passageway. The valve stem is normally held in a retracted position by spring 211. The valve is closed by activating coil 2 12 by means of a suitable electrical connector 213. After the one passageway has been closed, the remaining flow is caused to go through the other passageways which have not yet received the allotted amount of liquid.

The solenoid valves, the meters and the electrically fired shaped charges are connected by suitable wires to switching means generally indicated by the numeral 80.

The switching means is connected to the surfaces by means of conduit 81 which includes all the appropriate electrical connections. The electrical conduit is connected to the downhole electrical circuitry by means of a pin 82 and socket 83 arrangement. Concentric alignable rings such as rings 84 and 85 are provided to permit individual electrical contact of the various electrical cables leading to the downhole mechanisms. The switch means 80 includes an electric motor 91 having a rotatable shaft 92 for moving switch means 93 and 94 to various positions. The electric motor can be actuated from the surface. The electric switch has at least a neutral position, a shaped charge firing position, and solenoid valve actuating position. The switch is suitably arrange-d to permit individual closing of the solenoid valves. The wires to the meter means are run directly through the switch so as to always transmit information to the surface. The main purpose of the switch means is to reduce the number of electrical leads in conduit 81 that runs from the surface to the underground portion of the apparatus.

FIGURE 4 is a side elevation view of a portion of the preferred embodiment of the apparatus, and along with sectional views in FIGURES S, 6 and 7, illustrates the packing rings in an expanded position and the perforations in the casing formed by the shaped charge perforating means. As shown, packing rings 162 and 163 are in contact with the casing 101. The packing rings 1162 and 163 pack off a circular zone of the casing to prevent drilling mud in the annulus from entering the packed-off perforations. The packing rings are expanded by means of fluid pressure in passageway 56 and chamber 157 acting on piston 158. This pressure causes the piston 158 to move out of the chamber 157. Frame 114 is carried with the piston and the packing rings 62 and 63 which are mounted on frame 114 and are forced against the casing. The frame is normally urged into a contracted position in chambers 124 and 125 by means of springs '159 and 161 acting on flanges 122 and 123.

The shaped charge means when fired perforate the face plates .170 and 171 and the casing as illustrated by 301 and 302. Thus consolidation liquids may be injected into the formation at perforation 301 through passageway 166 and chamber 169. In a similar manner, fluid can be injected through perforation 302 by means of passageway 165 and chamber 168. As discussed above when the proper amount of liquid passes one of the meters, the solenoid valve on the particular passageway will be closed causing the remainder of the fluid to flow to the other perforations.

Although a specific embodiment of apparatus has been described, the invention is not to be limited to the embodiment so described but rather only by the scope of the appended claims.

I claim:

1. Apparatus for injecting liquid through perforations of a well casing comprising a main body member having a main flow path through at least a portion of its length, a plurality of pack-off means on said main body member extendible against a well casing to pack off selected perforations of said casing, a plurality of secondary flow passageways in said main body member for communieating with said main flow path and extending to each of said selected packed-off perforations of said casing, metering means on each of said secondary flow passageways for indicating the amount of liquid passing through each of said secondary flow passageways and valve means for selectively closing off each of said secondary flow passageways to liquid flow.

2. Apparatus comprising a main body member having a central fiow path through at least a portion of its length, a plurality of pack-off means on said main body member extendible against a well casing to pack off selected portions of said casing, perforating means to penetrate the casing within each of said selected packed-off portions of said casing, flow passageways communicating with the central flow path of said main body member and extending to each of said selected packed-off portions of said casing, metering means on each of said flow passageways for indicating the amount of liquid passing through each of said flow passageways and valve means on each of said flow passageways for selectively closing off each of said flow passageways to liquid flow.

3. Apparatus for use in injecting predetermined amounts of liquid into an earth formation penetrated by a cased well comprising a main body member having a central flow path through at least a portion of its length, connecting means for connecting said main body member with a string of tubing to form a flow path from the surface to the central flow path of said main body member, a plurality of pack-off means on said main body member extendible against the casing in said well to pack off selected portions of said well, means for extending said pack-off means, said means being actuated by pressure exerted on liquid in said central flow path, perforating means to penetrate the casing within each of said packedotf portions of said casing, flow passageways for communication between the central flow path of said main body member and each of said packed-off portions of said casing, resilient valve means in said central flow path normally closing said flow passageways, said resilient valve means being responsive to a predeterminable pressure on the liquid in said central flow path of said main body to open and to permit liquid to pass into said flow passageways, metering means on each of said flow passageways, and valve means in each of said flow pasage- Ways for selectively stopping flow through each of said passageways.

4. A method of injecting liquid into an earth formation penetrated by cased well, the casing of said well having a plurality of vertically-spaced perforations comprising the steps of packing off each of a plurality of selected perforations of the casing in said well, establishing a flow path from the surface to each of the packed-oft perforations, flowing a liquid substance down said flow path to each of the packed-off perforations and applying pressure to move said liquid through said perforations and out into the formation behind said perforati ms, metuingthmamount..-

of said liquid passing to each of said packed-off perforations and halting flow of said liquid to each of said perforations after a predetermined amount of liquid has flowed thereto.

5. A method of injecting liquid into an earth formation penetrated by cased well, comprising the steps of packing off each of a plurality of spaced-apart portions of the casing of the well, perforating the casing inside o feach of said packed-off portions, establishing a flow path from I References Cited by the Examiner UNITED STATES PATENTS 3,121,459 2/1964 Van Ness et a1. 166-35 X 3,181,608 5/1965 Palmer 16642 X 3,212,576 10/1965 Lanmon 16635 X ERNEST R. PURSER, Primary Examiner. 

4. A METHOD OF INJECTING LIQUID INTO AN EARTH FORMATION PENETRATED BY CASED WELL, THE CASING OF SAID WELL HAVING A PLURALITY OF VERTICALLY-SPACED PERFORATIONS COMPRISING THE STEPS OF PACKING OFF EACH OF A PLURALITYOF SELECTED PERFORATIONS OF THE CASING IN SAID WELL, ESTABLISHING A FLOW PATH FROM THE SURFACE TO EACH OF THE PACKED-OFF PERFORATIONS, FLOWING A LIQUID SUBSTANCE DOWN SAID FLOW PATH TO EACH OF THE PACKED-OFF PERFORATIONS AND APPLYING PRESSURE TO MOVE 